A truck may need at times to be towed, that is, lifted at and/or pulled from its front or rear end. Such occasions may occur during manufacture and delivery, during service in vocational applications, and at times when the truck becomes disabled for one reason or another. It is convenient to use a center tow attachment at the front of the truck, that is, a towing attachment located at or about a center of the truck's bumper.
With heavy trucks there is a need for the tow attachment to have a high load capacity.
It is desirable that the tow attachment assembly have a redundancy in the event of the failure of a component part.
The invention provides a tow attachment assembly for a heavy truck that fulfils these needs.
A tow assembly according to the invention includes an arrangement of two load bearing paths, configured as an inner load bearing member and an outer load bearing member, with a tow eye and an interface interconnecting the tow eye to both the inner member and the outer member in such a manner as to effectively split a load applied to the tow eye between the load bearing members. Preferably, the interface interconnects the tow eye, outer member, and inner member so that the load is divided approximately equally between the inner load bearing member and outer load bearing member.
According to one embodiment, a tow assembly includes an outer hollow member and an inner member disposed in the outer member, ends of the outer member and inner member being substantially coextensive, and a tow eye mounted on the outer member with an interface structurally interconnecting the tow eye to both the outer member and inner member.
An interface in accordance with the invention may include bolts that engage and fasten the tow eye, outer member, and inner member, the bolts extending through appropriately located holes in the outer member, inner member and tow eye. Nuts or other devices may be used to secure the assembly together at the interface location.
According to one embodiment, the outer member and inner member are tubular members, the inner member having an outer dimension less than an inner dimension of the outer member. The tubular members may be cylindrical tubular members or square or rectangular tubular members. To allow the load to be divided between the inner member and outer member, the inner member outer dimension is selected to allow relative movement between the inner member and outer member away from the interface location. The relative movement may be sliding movement if the relative dimensions are selected so that the members are in contact.
According to an alternative aspect, the inner member may be sized to provide a gap between the outer surface of the inner member and the inner surface of the outer member. The interface may include a short sleeve may be positioned between the outer surface of the inner member and the inner surface of the outer member at a location for mounting the tow eye. An interface sleeve is dimensioned to contact both the inner member and outer member to provide an interconnection between the inner member and outer member at a point where the tow eye is fastened.
According to another embodiment, the outer member may be formed as a square or rectangular tube and the inner member may be formed as an I-beam. The tow eye may be fastened to an outer face of the outer member and a flange of the I-beam.
According to another embodiment of the invention, an interface comprises a box-like structure having a front face, a rear face and oppositely located side faces and defining an interior space. An outer member includes a first tubular member attached to and extending from one side face of the interface, and a second tubular member attached to and extending from an opposite side face of the interface. An inner member is disposed in and extends through the first outer member, the side faces of the interface, which are provided with holes for this purpose, and the second outer member, the inner member being attached to the side faces of the interface. A tow eye is mounted to the front face of the mounting box and the interface further includes fasteners to structurally interconnect the tow eye, the inner member and the front face. Because the inner member and outer member are both attached to the side faces of the interface, load transmitted from the front face to the side faces is accordingly transmitted to the inner member and outer member. The inner member and outer member may conveniently be tubular in shape, but other shapes may be used.
According to another aspect of the invention, with a tubular inner member it is convenient to provide interface fasteners as U-shaped bolts engaging the inner member and having free ends extending through holes in the front face and holes in the tow eye, with nuts securing the bolts to the tow eye.
A tow eye as used here means a device to which a tow hook or cable can be attached. According to one embodiment, a tow eye includes a base plate, spaced upper and lower flanges extending from the mounting plate and mutually perpendicular, the upper and lower flanges having aligned apertures for a tow pin. The tow eye may also be configured as a mounting plate with an eye hook or other linking device mounted thereon.
According to the invention, the assembly is provided with brackets for mounting to a vehicle frame. The inner member and outer member are elongated members having opposite ends substantially co-extensive. A first mounting bracket is connected to a first end of the outer member and a first end of the inner member, and a second mounting bracket is connected to a second end of the outer member and a second end of the inner member.
According to an embodiment of the invention, the interface is disposed at about a center of the assembly. The interface may alternatively be located at any point or points along the member as is deemed appropriate for the intended use.
Alternatively, the invention may be adapted for use as a dual tow point assembly, by providing a second interface and a second tow eye. The first interface and first tow eye and second interface and second tow eye are mutually spaced, preferably from a center of the tow assembly.
The invention will become better understood by reference to the following detailed description read in conjunction with the appended drawings.